A cobporavxotf



April 22 1924. Re.l15,sz1

J. H. KENDIG PROCESS ANI) APPARATUS FOR DRAWING SHEET GLASS OriginalFiled July 19, 1916 tion; and

Reuma Apr. 2z, 1924.

UNITED STATES Re. 15,821 Ferca.

PATENT, lo

Juanma. xmwnrc, or nncnwoon, rrrrsnuaen, rmmsnvaN'ra, assrenoaro 'ran:ananEY-owmrs emr crass COMPANY, or rompo,- omo, a coaroaa'non or OHIO.

PROCESS AND APPARATUS FOB DRAWING SHEET GII-ABS.

Original No. 1,305,288, dated June 3, 1918, Serial No.

led June 1, 1821.

To all. 'whom t may concern.'

Be it known that I, JULIAN H. KaNnm, a citizen of the United States,residing at Edgewood, Pittsbur h, in the count of Allegheny andState oPennsylvania, ave invented certain new and useful Improvements inProcesses and Ap aratus for 'Drawing Sheet Glass, of whic the followingis a specification.

This invention relates to a process and apparatus forl drawing sheetglass, and has for its principal objects the provision of a process andapparatus whereby glass may be continuously drawn from a tank in theform of a flat sheet; the provision of an apparatus whereby the glass issupported while being drawn for the purpose of maintaining the glass inthe form of a fiatsheet, without marring the surface thereof; theprovision of a machinethat will form at a minimum of cost, sheet glass,free of blemishes and uniform inthickness, and such other objects as mayhereinafter appear.

One embodiment of the invention is illustrated in the 4accompanyingdrawings, whereinz- Figure 1 is a side elevation of the apparatusshowing thetank and leer in sec- Fig. 2 is a section on the line II-IIofFigfl. l The apparatus comprises a tank 1 containing a body of moltenglass 2 which is maintained at a constant level by yany convenientmeans.

The delivery end of the tank is` open at its front end to permit glassto ow over the` top edge of the` front wall 3 while the a'pparatus isinoperation. A gated` is provided to extend across the end of theVtank'for thel purpose of closing the discharge opening when theapparatus is not in operation. Then the a paratus,` is in operation, thegate 4 is held beneath 'the' surface of' the glas by any convenientmeans, vand when it is desired to shut 0E the flow of glass, the gate 4is elevated so that the top edge thereof lprojects labove the surface ofthe glass.

skimmer 5 extends from one side ofthe tank to the other and is for thepurpose of preventing the `impure surface glass from flowing out of thetank. lThe glass passing to lthe drawing opening, therefore, must110,098, tiled July 19, 1916. Application for reissue Serial No.474,228.

come from beneath the surface where the purest glass is obtained.

A cylindrical supporting roll 6 is positionecl adjacent the end wall v3so that the axis thereof is approximatel on the same level as the glassinthe tank, and so that the surface of the roll almost touches the tooutside corner 7 of the end wall. The rol consists of a supporting rimor cylinder 8 carried by the spokes 9 and is rovided with a bearin shaft10 exten ing through the centert ereof and pro'ecting beyond the ends ofthe roll. Upon t e rim or cylinder 8 is mounted a series et planks 11made preferably of bass wood, or a composition of bass wood sawdust andm0- lasses, which has been baked in molds. Any.

substance that is non-heat conducting and will not scratch or score theglass might be substituted, but it has been found that bass wood or thecomposition just referred to or any substance that will be carbonizedwith a smooth char vis preferable.

The planks or blocks 11 may be secured to the rim 8 by any suitablemeans, and are preferabl sawed or molded lwith curved sides wit aportion of one of the .curved sides cut away to form a deep narrowgroove 12 between each plank or block. .When the ,planks are mountedupon the rim, the

grooves 12 will be curved kas shown in Fig. 2, and the reason for thecurved grooves will `hereinafter appear.

The roll is mounted for rotation upon movable bearings 13 through whichthe ends of the shaft lproject, and suiiicient space is rovided betweenthe bearings and the end; of the roll so thatthe roll may be moved backand forth in the direction of its A axis and transversely of the tank 1.The bearings 13 are slidably mounted upon bases 14 and are adapted to bemoved toward and away from the tankl by means of thescrews 15 which arethreaded through the bearing and supported and held against longitudinalmovement by the base. When the wheels 16 are simultaneously turned thebearings willvfbe moved either toward or away from the end of the tank.Because of this adjustment the surface of the roll can be maintained atthe vproper distance from the front end wall of the tank. a

Sheet glass Ais formed as follows: A cold ysheer. of glass is pndbetween the. drawing roll at 19. The heat of the glass will'charA orcarbonize the surface ofthe planks or blocks uniformly over therevolving surface thereof `but the blocks are burned only to a limiteddepth because the` surface is continuously moving and is being cooled b`the surrounding air when not in contact with the glass. After a smooth,velvety, uniform char has been formedon the entire surface of the roll,it is in condition for the forming of a glass sheet. j The drawing rolls17 and 18I are now turned so as to lower the cold sheet, which serves asa bnitf into the glass for the purpose of startin a sheet of glass thesame width as the eo dsheet or bait. Viren the glass' has adhered to thelower edge of the coldfsheet, the rolls 17 and 18'are reversed so thatthe lastic sheet will be slowly drawn over t e surface of therevolvingmoll 6.

u 'Iihe roll 6 is turned so that the surface thereof moves considerablyfaster than the`glass.

being drawn over' it. Therefore, each article of the under surface ofthe glass is eing continuously rubbed or stroked in a path parallel'with thepath of lthe draw and is prevented from moving toward thelcenter of the sheet by the tendenc of the roll` to maintain it in astraight pat parallel to the vmaintains its 'original width`indefinitely.

The glass adjacent the surface will tend to cling to the side wall ofthe tank and will draw out slightly as at A. vThis formation assists inmaintaining the full width of the sheet `at the point where the mainbody of glass. y

A further condition Vwhich assists in maintaining tlie glass in sheetform is the contact which the glass has with the roll' at 19 beneath thesurface of theglass. The glass is partially 'cooled throughoutv thewidth of the sheet beneath the surface and therefore receives an initialhardening in `sheet form before it leaves the surface of the glass. Thisg ass from the surface of. the rglass in thev tank.

glass 'leaves the The curved grooves 12 re provided to stroke the glass'way from the center toward the edges when the .roll isyturned ant'i-\lclockwise, to assist inpreventing the particles of glass from movingtoward the center o ffthe sheet. It is preferable to turn the roll sothat the surface thereof moves in the direction op osite to that inwhich the glass is being drawn. blrt`the rollmay be turned in thereverse direction. in which event the roll should be reversed so thatthe curved grooves thereof will always tend to stroke.

the glass, awav from the center. Another function of the-groove is toconduct any gases formed by the combustion of the wood away from theunder-side of the glass.

Because the surface of the'roll moves at a higher velocity than thesurface of the glass, the sheet is maintained at its original width, andis atthe same time polished while being formed. The roll is alsoprevented from burning on account of this relative velocit)7 of the rollwith respect to the glass.

Assuming that a sheet of glass has been drawn past the rolls 17 and 18by the cold sheet bait the, operation is thereafter continuous. Therolls 17 and 18 continue to turn in the `direction of the arrows, andcontinuously draw'the glass sheet 20 overI the roll 6 and deposit it uon an endless belt carrier 21 to be hereina ter described.

The driving rolls 17 and 18 and the carrier 21T which are merely showndiagrammatically, maybe moved so that the point of tangency of the sheet20 with respect to the roll 6 may be shifted tousuit operating s houldnot leavethe wheel surface until it is just ready tofset or become hard,so that the sheet is stretched straight before it finally hardens,YA Forthe purpose of controlling the temperature of the sheet so that it willset or harden just after it leaves the wheel orl at the point marked S.va gas burner 22 and air pipes 23 and 24 are -provided. They flow of gasis regulated bythe valve 25 conditions. but itis preferable that theglass and the air pipes 23 and 24 are controlled by p valves 26 and 27,respectively. By manipulation of these valves the temperature of thesheet may be regulatedl and the, glass kept from cooling abruptly. Meansfor absorbing the heat, such 'as water cooled tubes placed adjacent thesurface'.y of the glass. may be used in plate of the air pipes forregulating the temperature of the sheet. One reason for preferablyturning the wheel 6 so that-its surfacev moves in adirection opposite tothat in which the glass is being drawn will be seen from the following.

Assumingmthat the glass is set hard above "thepoint S, and suicientlyset below the point S to the point C to prevent the cohesive action ofthe molecules from drawing l the molecules toward the center of ythesheet-y then the space in which there is a tendency for the cohesion Vofthe molecules to .draw them toward the center of the sheet is-betweenthe point C and the surface of the glass 2. A chain of moleculessuspended themolecules toward the edge of the glass.

After the glass passes the rolls 17 and 18, it passes upon the carrier21 which consists of a pair of rollers28 and 29 supported upon a frame30 which is pivoted upon a shaft 31.y An endless belt 32 passes over therolls and is adapted to support the glass f sheet. When the glass sheetextends to the roll 29,'it is cut b any convenient means at the point X.e carrier is then moved downward about the shaft 31 by means of the rod33 pivoted to the lever 34 secured to the carrier frame 30. When thebelt 32 assumes the position indicated by the dotted line, the gear 35on the roll 729 will mesh with the `gear 36 as indicated. The gear 36 iscontinuously r tated and will drive`r the endless belt 32, hereby moving.the glass sheet onto the carrier 37. ducts the sheet through a suitableleer 38 for the ur ose of permitting the glass to cool gra ual y. Afterthe sheet has been' delivered to the leer carrier, the framev 30 isagain elevated to receive and support the sheet being drawn. The rolls17 and 18 and the carrier 21 may be incased in a suitably heated oven or'extension of the leer to prevent sudden cooling of the glass as it isbeing drawn.

The temperature of the surface of the roll is regulated by means of oneor more air blasts 39 arranged beneath the roll at suitable locations,and to insure uniform Wearing;r of the surface,the roll is moved backand forth longitudinally quite slowly las the glass is being drawn..

It is obvious that the process may be carried out by a machine ofdifferent design and construction and many changes may be made in thedetails of operation and construction without departing from the spiritof thc invention. and thc invention is therefore not limited to' thespecific construction herein illustrated and described.

l claim as my invention l. The herein described process ofvmaking sheetglass which consists in drawing a plastic sheet of glass directly from.the surface of a body of molten glass upwardly, while plastic. over asmooth supporting surface that will not meu' the glass. inclined fromthe perpendicular so as to support the This carrier cons 'glass in sheetform substantially from` the point of emergence from the body of glassto a remote point. in moving the supporting surface which is in contactwith the glass with respect to the glass while the lglass is beingdrawn. and in permitting the glass to cool.

2. The herein described process of making sheet glass which consists indrawing a plastic sheet of glass directly from the surface of a body ofmolten glass upwardly, while plastic, overV a carbonized supportingsurface inclinedv from the perpendicular so as to support the glasssubstantially from the point of emergence from the body Iof glass to aremote point, in moving the supporting surface which isv in contact withthe glass with respect to the glass while the glass is being drawn. andin permitting the glass to cool.

3. The herein described process of making sheet glass which consists indrawing a plastic sheet of glass directly from the surface of a body ofmolten glass upwardly over a roll having asupporting surface thatrwillnot' mar the glass'disposed so as to support the glass in sheet formsubstantially from the point of emergence from the body of the glass toa remote point, in turning the roll so that thevsurface thereof which isin contact with the glass-has relative movement with respect to theglass while the glass v-is being drawn, and in permitting the glass tocool. f

4. The herein described process of making sheet glass which consists indrawing a plasf glass while the glass is being drawn, and in fpermitting the glass to coo The herein described -process of makingsheet glass which consists in drawing a plastic sheet of glass out 'of abody of molten glass, in supporting the sheet of plastic glass from thepoint where it leaves the body of molten glass v'substantially to thepoint where the glass hardens. upon a smooth surface, in moving thesupportingr surface with respect to the glass While the glass is being Vdrawn and in permitting the glass to cool.

6. The herein describedprocess of making sheet glass which consists indrawing a plastic sheet of glass out of a body of molten glass, insupporting the sheet of plastic glass A from the point where it leavesthe body'ofr molten glass substantially to the point where y,

the glass hardens. upon a carbonized porting surface, inmovingmthejsupporting" Aglass from the point where it leaves the body.of molten glass substantially to the poi'nt vwhere the glass hardens,upon a portion of the surface of a cylindrical roll havingla smoothsurface, in turning the vroll so t the surface thereof has relativemovement with respect to the glass while the glass is being drawn, andin `permitting the glass to cool.

8. The herein described process of making sheet glass which consists indrawing a plastic sheet of glass directly from the surface of a body ofmolten glass upwardly, while plastic, over a roll having a supportingsurface of soft carbon disposed so as to support the glass substantiallyfrom the point of emergence from the body of glass to a remote point, inturning the roll so that the surface thereof which is in contact withthe glass moves in the direction opposite to that in whichthe glass isbeing drawn, `and in permitting the glass to cool.

9. The herein described process of making sheet glass which consists indrawing a lasticsheet of glass directly from the surace of a body ofmolten glass u wardly over a cylindrical roll having a vsur ace thatwill not mar the glass and so disposed as -to support the glass in sheetform substantially yfrom the polnt 'ofemergence from the body of 'theglass to a remote point, iny turning the roll so that the surfacethereof which is -in contactv with the glassV has relative movement withrespect to the lass and in permitting the glass to harden just after itleaves the curved surface ofthe rollll.

10. The herein described process Vof making sheet glass which consistsin drawing a plastic sheet of glass. directly from the surface of a bodyof molten glass, in drawing `thel sheet while plastic upwardly over acylinder having a surface composed of a substance adapted to beca-rbonized by the heat of the glass and disposed so as to support theglass substantially from the point of emergence from the body of theglass to a remote point, in turningl the roll so as to intermittentlymove the particles of the surl face out of contact with` the glass toretard combustion thereof, and in permitting the glass to' cool.v t y11. The herein described process of making sheet glass which'consists indrawing a plastic sheet ofglass directly from the surface of a/ body omolten glass, in drawing the/ sheet upwardly'ffwhile plastic over asmooth relatively non-"heat conducting supporting surface disposed at anangle from the perpendicular so as to support the glass i glass whilethe glassis being drawn, and

in permitting the lass to cool.

12. The herein escribed process of making sheet glass which consistslindrawing a plastic sheet of glass out of a body of molten glass, indrawing the sheet over a smooth supporting surface while plastic,finstroking the entire sheet of glass in a direction from the center .ofthe sheet toward the edges thereof while plastic and in permitting theglass to cool.

13. The herein described process of making sheet glass which consists indrawing a plastic sheet of glass upward out of a body of molten glass,in stroking the entire sheet of glasstin a direction from thecenter ofthe sheet toward the edges thereof while plastic and in permitting theglass to cool.

14. The herein described process of making/,sheet glass which consistsin drawing a plastic sheet of glass upward out of a body of moltenglass, in drawing the sheet over a roll having a,V smooth supportingsurface the glass, in separating the sheet from the roll tangent to thesurface thereof at an angle less than a right angle to theperpendicular, in supporting the glass'in the plane of tangency as itseparates from the surface of the roll, and in permitting the glass tohalrden directly after it separates from the ro l.

15. The herein described process of makA ing sheet glass which consistsin dra-Wing a plastic sheet of glass upward out of a body of moltenglass, in drawing the sheet over a roll having a smooth supportingsurfaceV in contact withthe surface of the body of the glass, inseparating the sheetl from the roll tangent to the surface thereof at anangle ,less than a right angle to the perpendicular, in supporting theglass in the plane'of tangency as it separates from the surface of ,theroll, in permitting the lass to harden directly after it separates romthe roll, in severing the glass in sections while suppotted in the planeof tangency and in lowering the sections to the horizontal plane afterit yhas been severed.

16. In combination with a machine for drawing sheet glass having a tankfor coli-v 'in contact with the surface of the body of' tact with the.glass beingiada ted to be4 moved with respect to the sur ace of theglass in contact with the roll.

17. In combination with a machine for drawing sheet glass having a tankfor containing molten lass and a means for drawing glass direct y fromthe surface thereof,

Aa continuously turning roll provided with a surface that will not marthe glass and dis posed so as to support the plastic glass in sheet formas it being drawn substantially from the point of emergence of the sheetfrom the molten lass to a remote point, the surface of the ro in contactwith the glass bein adapted to be moved in a direction oppose to thedirection in which the surface of the glass in contact with the roll isbeing drawn. 1

18. In combination with a machine for drawing sheet glass having a tankfor containing molten glass, and a means for drawing g ss therefrom, aroll adapted to be continuously rotated in contact with the sury face ofthe molten glass for. supportin the plastic glass in sheet form as 1t iseing drawn upward over the roll, provided wit a surface ada ted to becarbonized by the heat of the ass in contact therewith, the said surfaceaving relative movement with the glass in contact therewith.

19. In combination inl a machine for drawing sheet 'glass having a tankfor containing molten glass and a means for drawing glass therefrom, aroll adapted to be continuously rotated for supporting the plastic glassin sheet form as it 1s being drawn provided with a surface havinggrooves on the surface thereof arranged so that the edges of the grooveswill stroke the glass from the center of the sheet toward the edges asthe glzlilss is being drawn over the surface of the ro v 20. Incombination in a machine for drawing sheet glass having a tank forcontainingmolten glass and a means for draw in lass therefrom, acontinuously turning ro 1 or supporting the plastic glass in sheet formas it isbeing drawn provided with a surface having curved grooves on thesurface thereof arranged so that the edges of the grooves will stroke`the glass from the center of the sheet toward the edges as the glass isbeing drawn over thesurface of the roll. i

21. The herein described process of makin sheet glass which consists inplacing a ro l having a surface that will notI mar they glass adjacentthe discharge openin 4that the surface thereof in contact with the glasshas relative movement with respect to the glass in contact therewith.

22. The herein described'pro'cess of makro having a surface that willnot mar the glass adjacent the dischar openin of e tank containingmolten ass, in owing molten glass through the ischarge opening againstthe surface of the roll, in drawing a sheet of glass out of the tankupwardly over the surface of the roll above the surface of the moltenglass, and in turning the roll so that the surface thereof in contactwith the glass moves in a direction opposite to the direction in whichthe glass is being drawn. K y

23. A machine for drawing sheet glass comprising in combination, a tankfor containing molten glass provided with a lateral discharge opening, aroll havin a surface which will not mar the glass a jacent the dischargeopening so as to engage the horizontal surface of the lass in the tankand having a portion of its surface extending above the surface of theglass in the tank, and means for drawing a sheet of glass from themolten glass upwardly `over the roll -as the roll is rotated.

24. A machine fordrawing sheet glass comprising in combination, a tankfor containing molten glass, a support in engageA ment with the glasshaving a portion of its surface inclined at an angle to theperpendicular above the surface of the glass, means for drawing arsheetof glass upward over the supportlat an angle less than a right angle tothe perpendicular, means for supporting the glass at the prescribedangle while being drawn, and means for lowering the glass to ahorizontal position afterthe sheet is drawn.

25. A machine for drawing` sheet glass comprising in combination. a tankfor containing J'nolten glass, a roll having` a surface that willnotvmar the glass in engagement with the surface of theglass having aportion ot its surface above the surface of thc glass, means tor`drawing a sheet of glassl upwardly over the surface of the roll and outof engagement thcrewithat an angle less than a right angle to theperpendicular', means for supporting a sheet at the prescribed angle`while boing drawn. and means for lowering the sheet., to asubstantially horizontal position after thc sheet has been drawn. p r

`26. The herein described process of`d`rawing sheet glass whichconsistsin placing a support having a surface that Awill not mar the glassadjacent the dischargel opening of `a tank containing nmltcn glass sothat it.

)rojects above thc surface thereof. in flowing molten glasshorizontally' tlirougli`-t|1cy sheet glass which consists` in placing ainn lll)

combination with means for drawing a sheetv of glass upwardly from asupply of molten glass, of a support over which the glass is` rawn andhaving a supporting surface adapted to be moved faster than the Y'glassand infthe opposite direction to the `movement of the glass.

` 28. In a sheet glass forming ap aratus, the combination with means forrawing a sheet of glass from a supply of molten las,l of a roll overwhich the lass is rawn adapted to be rotated at a iferent surface speedfrom that of the glass.

29. In a sheet glass forming apparatus, the combination with means fordrawing a sheet of lass from a sup ly of molten glass, of a ro overwhich t e glass is drawn adapted to be rotated in the opposite directionfrom that in which the glass isdrawn.

30. In a sheet glass forming apparatus, the combination with means fordrawing a ksheet of glass from a supply of molten glass, of a su portover which the glass is drawn adapte to polish the surface of the glassin contact therewith, the support being movable in the oppositedirection from that in which the sheet is drawn to increase the rate ofsliding contact between the sheet Aand sup ort.

31. The herein described process of drawing sheet glass which consistsin forming a sheet of and moving the support in the direction o positeto the direction of travel of the cov.

s eet, whereby the sheet slidably en ges the support and is smoothed asit is. eing drawn.

32. In sheet glass forming apparatus, the combination with means fordrawing a sheet vof (glass from a supply of molten glass, of

rection changing roll over which the sheet of glass is drawn, adapted tobe rotated at a different surface speed from that of the glass.

33. .The combination with means for drawing a sheet of glass from a tankof molten glass, of a directionchanging device having a curved surfaceover which the sheet listhen passed and by which the direc-4 ltion ofthe sheet is changed while the glass is soft and plastic, said surfaceconsisting of a material permittingrelative 'sliding movement of thesaid surface and the surface of the glass in contact therewith while theglass is in said soft, plastic condition, means to rotate said deviceand thereby cause said sliding' movement, and means to keep said surfaceof the said device at a low enough temperature to prevent itsdestruction by the heat of the glass.

j34. In a sheet lass forming apparatus, the combination with means fordrawing a lass, drawing it over a support,`

sheet of glass from a tank of molten glass, a bending roll over whichthe glass isdrawn and by which its direction is chan ed, the

glass engaging surfaceot 'the rol being` the sheet is drawn and by whichits direction is changed and adapted to be reciprocated as thc'rglass isdrawn thai-cover.

36. The combination with means for drawing a sheet of glass from a supplof moltenjglass. of a bending device over w ich the sheet is drawn andby which its direction is changed and adapted to be reciprocated in adirection `transverse to that in which the sheet is drawn thereover.

37. The combination with means for drawing a sheet of glass trom asuppl' of molten glass', of a bending roll over w ich the sheet is drawnand by which its direction is changed and adapted'to be simultaneouslyrotated and reciprocated in the direction of its length. t

38. The combination with m'eans for drawingla sheetof glass from a supplof molten glass, of a bending device over w ich the sheet is drawn andby which its direction is changed, and means for moving the de vice in asubstantially horizontal plane transversely of theY sheet.

39. The cdmbination with a machine for drawing sheet glass having a tankfor containing molten glass and a means for drawing a sheetof glassupwardly therefrom, of a means disposed between the drawing means andthe point of origin ofthe sheet and moving transversely over the surfaceof the sheet for smoothing the glass after it is drawn from the tank. y

40. The combination with a machine for drawing sheet glass having a tankfor containing molten glass and a means for draw ing,.a sheet of glassupwardly therefrom, of a means disposed between the drawing means andthepoint of origin of the sheet and moving transversely over the surfaceof the sheet for smoothing the glass before it cools. z

41. The combination with a machine for drawing sheet glass having a tankfor containing molten -glass and a means for drawing a sheet of glassupwardly therefrom, of a means disposed between the drawing means andthe vpoint oforigin of the sheet and'moving in the direction of thesheet over the surface of the sheet for smoothing the glass after it isdrawn fromtb-e tank.

ft2-The combinationwith a machine for vdrawing sheet glass having` atank for conilo means for moving them with respect to the glass. Y 44.4.The combination with means for drawing a sheet of glass, of a bendingdevice over which the sheet is drawn comprising a series of spacedsmoothing blocks for engaging the surface of the sheet and for strokingthe sheet in a direction lengthwise thereof.

45. The combination with means for continuously drawing a sheet ofglass, of means for smoothing or flattening the sheet cornprising aseries of flattening bars arranged to successively engage a surface ofthe sheet and move in contact therewith in a direction lengthwise of thesheet.

46. A 4machine for drawing sheet glass comprising in combination a. tankfor containing molten glass provided with a lateral dischargeopeningjfa".` roll having a surface adjacent the discharge opening forengaging the horizontal surface of the glass in the tank and having aportion of its Surface extending above the surface of the lass in thetank, and means for drawing a. s eet of glass from the molten glassupwardly over the roll as the roll is rotated.

47. The combination with means to draw a sheet of glass, of a devicehaving a curved surface over which the glass is drawn while in a softplastic condition, said surface oonsisting of a material permittingrelative sliding movement of' `said surface and the surface of the glassin contact therewith While the glass is in said condition, meansformoving said device transversely to the direction of travel of theglass as the latter is drawn thereovelgand means to prevent overheatingof said device.

In testimony whereof, I have hereunto subscribed my name this 31st dayof May,

